7 Magnitude quake in oaxaca
Just swayed with the quake, preliminary info it was a 7 in the state of Oaxaca, will update as info is available, lets hoppe that there are no victims.
navegator
navegator
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- According to the study done by the Seismology department of the UNAM the Cocos plate had a displacement of 2.15 meters on the epicenter, that comes out to 7 feet and 3/4 of an inch of movement under the American plate.
navegator - Volcanos in Mexico are all strato volcanos, can be explosive as is mount St Helens, although they are relatively queit latelly with Popo venting ash, I remember going from Mexico City to Orizaba to grandmas and my brother and I would always see if the Popo was saying hello with a "fumarola" smoke, the name Popocatepdtl means smoking mountain, Pico de Orizaba, Citlaltepetl mountain of the star.
A couple of weeks ago more or less the Popo had lava flowing down the side, some volcanic tremors and high columns of ash, Don Goyo as he is afectionatly called is restles, need to apece him with some sacrifives, some tacos de huitlacoche and some pulque should be good, a comer señores!
Some volcanos are dormant and some active, I do not have info right now on who are asleep and whos restless, and yes the UNAM Universidad Autonoma de México has a large Geophisical deparment and a seismological department, very impresive.
navegator - P waves and Q waves and a pan half full of water guessing at the direction of the epicenter...
The pan needs to be set on something extremely sturdy and the soil beneath the structure must not be subject to liquifaction (i.e. set on bedrock)
I understand UNAM has a sizeable Seismology department within its geology structure. Volcanology too. Would love to visit. Have there ever been any Plinean eruptions in Mexico? Volcan de Fuego, Popo, and Paricutin all seemed to not involve catastrophic ejecta.
Looking at Youtube videos it amazes me of the number of ignorant Europeans who ignored obvious signs of an impending tsunami at Phuket Thailand. Then there are ignorant backpackers who insist on hiking up to the crater lip of unstable volcanoes. Poof! Pyroclastic hiccup.
I was given a gift of an entire ensemble of MRE's by a friend. 24 different meals, 2-cases. Aduana had a fit when they discovered the two cases -- tried to insist they were for military use only. They repose on a rat proof shelf high in the kitchen. Most probably they would be used after a hurricane. But with huge chest freezers and a generator, food is in 3rd place after drinking and domestic water.
My little casita has strategically placed inner walls and about 200' of 3/4" rebar in the concrete roof cap. Another 500' in the walls. Six-sack cement construction with inland rather than salt laden gravel and sand.
It pays to learn about possible regional hazards and the reality of the most common inconveniences and problems should a disaster strike. I have an industrial size JUEGO de PRIMER AUXILIOS (First Aid Kit). "Where There Is No Doctor" book in Spanish. - As the tsunami waves near the shallow coastal areas they intensify in velocity and shorten in wave length, when they arrive on to shallow water the energy in the wave is compressed and magnified.
DEPTH...............VELOCITY................WAVE LENGHT
in Meters...........Km/hour.................KM
7000................ 943.................... 283
4000................ 713.................... 213
2000................ 504.................... 151
200................ 159.................... 48
50................ 79.................... 23
10................ 36.................... 10.6
After the quakes and tsunami from Banda Ache more and more coastal communities are aware of the relation between a quake that is felt and the governments issuing tsunami warnings for areas that are farther away from the epicenter, more and more seismic stations need to be implemented along some of the more active zones 1 to have warnings and 2 to be able to study the movement of the earths crust.
After the 8.+ quake in Chile the earth rang like a giant bell with the waves bouncing back and forth for several days, although the earth has a very low frequency resonance, the earthquake waves travelled long enough for the geologists to map the vertical cores of molten magma and some features that were unknown at the time, this is very interesting for me, I love earthquakes unfortunately I tend to sleep through most of them you can fire a canon next to me and I will not steer, but I react to my wife telling me to turn in order not to snore, interesting!
Hasta la proxima sacudida asi los dejo quietecitos.
Until the next shaking so I leave you very still.
navegator - My dad always told us this when we were young:
If are you at the coast and the water in the bay starts to go out, you run the opposite way as fast and as high as you can, there is a "tidal wave" coming back very big and high.
They used to call them "tidal waves " back then until they changed to Tsunami, there is a you tube video of the Fukushima wave entering a small bay and marina I do not remember if it is California or Oregon, and the little wave seems so small until you see the power that it has as the boats docked and docks start to go every which way being tossed around, next time you are at the beach stand on the sand a foot beyond were the waves start to go back and feel the tug of the water it will change your mind about the power of mother nature.
Live long and prosper.
navegator - The surge onto La Manzanilla was so drawn out Mexicans moved furniture and appliances clothing and cars to high ground as the water was rising. It took more than an hour. There is a "Maremoto" warning system for sismos but I sure wouldn't risk my life about it working.
A temblor with regular shaking cadence indicates the epicenter is not close. If the shaking is vigorous and seems to be in tempo the quake might be distant and huge. Time to bail 3 miles inland ASAP. Abandon chairs and site bling it isn't worth your life.
Having been in the Hebgen MT and three or four others 6.0+ I can vouch for the fact a nearby epicenter is NOT rhythmic (sp). It's YANK shake shake YANK YANK! The longer the "fetch" at sea with a big quake the more time until it hits. Sometimes progressively bigger surges. At night a big quake is especially scary.
Videos of the Fukishima disaster made what little hair I have left, stand on end. - After the La Manzanilla quake, we were on our way south, and did what homework we could do with early internet. We were able to discover that the crown on the cathedral in PV had toppled, nothing more.
When we got around the Melaque area, we saw huge piles of stuff-vehicle/tractor parts, pipes, basic debris, on the side of the road in HUGE piles. When we got to Boca de Iguana, we spend some serious time with the late Michele. We had gone through the US Gulf War there and knew him. We asked him about the tsumani, and when, at his request, changed from English to Spanish, were shocked at the extent of the wave. Fortunately, he and his family had moved inland to "properly" educate their children and had employees taking care of the park. We can both still picture what he told us about what happened.
The two of us have advanced degrees in marine biology, and supposedly understand what the ocean can do. We have always lived on the beach, formerly in California, now permanently in Zihuatanejo.
The ocean is a wonderful, fabulous, harsh mistress. Mother Nature is not to be ignored. Live well and respect her! - I was loading Quicksilver for Mexico when the Loma Prieta quake occurred and had returned the Lozenges area when Northridge hit. One thing about an RV it intrinsically has better survivability if nothing topples onto it. Furniture doesn't slide or fall and the onboard logistics softens rude cuts in utilities.
And just for drill, Zihuatanejo has suffered a 20'+ tsunami* in years past and La Manzanilla Jalisco saw an 8'+ tsunami around 23-years ago. Any place there is a tetonic subduction, there is risk of tsunami.
*It reached as far inland as Mex 200 - Earthquakes in the areas of Oaxaca and South encompassing the bay of Tehuantepec and Northern Guatemala are very common that is where the tectonic plate of Cocos sinks under the American Continent.
In Oaxaca there are some tombs in a place called Mitla, they are built in a cross and the interesting features are the roof slabs that are not supported by the stone wall slabs, rather there is a gap of one inch or more between the wall and the roof slab that prevents the roof slabs from moving or tumbling the walls, so this was a known phenomena to the Zapotecas, there will always be earthquakes in Mexico after a while you notice the telluric movement and just go on, or go out side where the high voltage lines sway rhythmically, asi es Mexico!
navegator
